1. Field of the Invention
The present invention relates to a method for connecting an incoming call in a wireless communication device to a dual mode terminal apparatus that can be operated both as a wireless terminal apparatus of the wireless communication device and as a mobile radiotelephone terminal apparatus of a mobile radiotelephone network.
2. Description of the Prior Art
Such terminal apparatuses, called dual mode hand apparatuses (Dual Mode Handy) or dual mode terminal apparatuses, have recently been offered by some manufacturers. A dual mode terminal apparatus is a communication terminal apparatus provided with a transceiver unit and a coding/decoding unit for a mobile radiotelephone network, provided and with another transceiver unit and another coding/decoding unit for a stationary wireless communication system. As a mobile radiotelephone network, a network is typically provided according to the Global Standard for Mobile Radiotelephony GMS with approximately 0.9 GHz carrier frequency, or according to a standard DCS1800 with approximately 1.8 GHz carrier frequency. As a wireless communication system, a digital wireless communication system according to the ETSI standard for digital expanded wireless communication DECT (Digital Enhanced Cordless Telecommunication) is used. Such a terminal apparatus can be switched between the two operating modes (wireless operation or mobile radiotelephone operation), whereby among other things the dialing device and the electro-acoustic transducer of the terminal apparatus are used in both operating modes.
If an incoming call in the wireless communication device is to be connected to a dual mode terminal apparatus, the wireless terminal apparatus must be ready for operation within the radio area of the wireless communication device in wireless mode. If a subscriber wishes to receive a call coming in for the dual mode terminal apparatus in the wireless communication device at a different terminal apparatus or to receive it in mobile radiotelephone operation, in certain known communication networks, and particular in digital service-integrated communication networks, he can cause a call forwarding to this other terminal apparatus or to the same terminal apparatus via a different communication network. However, this is relatively expensive, so that many subscribers set up such a call forwarding only occasionally.
It is also possible to set up the wireless communication device with respect to a subscriber connection in such a way that when a call is coming in; in the wireless communication device, a prompter call is signaled for a certain period of time to the terminal apparatus for which the call is coming in, and a call forwarding is automatically carried out after this time period expires. This has the disadvantage that, within this certain time period, the called subscriber must accept an incoming call if he wants to prevent this call from being rerouted via the mobile radiotelephone network. A further disadvantage of such a procedure is that if a call coming in in the wireless communication device cannot be delivered within a certain time period, a signaling takes place for a connection set up between two different communication networks, independent of whether the subscriber can be reached in the mobile radiotelephone network or not. As such, the communication networks are unnecessarily burdened.
The object of the present invention is to device [. . . ] a method for connecting a call coming in in a wireless communication device to a terminal apparatus that can be operated both as a wireless terminal apparatus of this wireless communication means and also as a mobile radiotelephone terminal apparatus of a mobile radiotelephone network. In this way, unnecessary connection setup signalings between the wireless communication device and the mobile radiotelephone network are to be avoided as far as possible.
According to the present invention, therefore given current availability of the dual mode terminal apparatus in the mobile radiotelephone network, a message concerning such availability is sent to the wireless communication device, and an item of information concerning the availability of the terminal apparatus via the mobile radiotelephone network is stored in the wireless communication device. Given a call coming in for the terminal apparatus in the wireless communication device, it is checked within the wireless communication device whether an item of information is present relating to the availability of the terminal apparatus via the mobile radiotelephone network and, if the terminal apparatus can be reached via the mobile radiotelephone network, the incoming call in the wireless communication means is forwarded to the terminal apparatus in the radiotelephone network.
A development of the present invention addresses to the case in which the wireless communication device in which a call is coming in for a communication terminal apparatus is the home wireless communication device with relation to this terminal apparatus. As such, this terminal apparatus also can be operated at at least one further wireless communication device, i.e., is registered there. In a further development of the inventive method, the further wireless communication device sends a communication to the mobile radiotelephone network if the terminal apparatus can be reached in the area of this additional wireless communication device, and the mobile radiotelephone network communicates a message concerning the availability of the terminal apparatus to the home wireless communication device. If the mobile radiotelephone network has communicated an item of information concerning the availability of the terminal apparatus in the area of the additional wireless communication device to the home wireless communication device, the call is forwarded to the additional wireless communication device by the home wireless communication device.
In yet another development of this form of the inventive method, it is provided that a call is always forwarded from the home wireless communication device into the mobile radiotelephone network if a message concerning the availability of the terminal apparatus has been communicated from the mobile radiotelephone network to the home wireless communication device, and that the call forwarded from the home wireless communication device in the mobile radiotelephone network is forwarded from the mobile radiotelephone network to the additional wireless communication device, if there is present in the mobile radiotelephone network an item of information concerning the current availability of the terminal apparatus via this additional wireless communication device.
The last-named variant of the inventive method ensures that from the mobile radiotelephone network to the home wireless communication device it is always the case that only one message is required indicating that there is knowledge in the mobile radiotelephone network concerning the availability of the terminal apparatus. A message concerning the actual location of availability of the terminal apparatus then need be transmitted only from the corresponding wireless communication device to the mobile radiotelephone network.
Another development of the present invention provides that a call coming in for a communication terminal apparatus in the home wireless communication device is switched to a manually set forwarding destination given manually set call forwarding in this communication means.
The wireless communication device of the present invention contains a controller in order to automatically activate a call forwarding to the terminal apparatus in the mobile radiotelephone network upon receipt of an item of information concerning the availability of the terminal apparatus via the mobile radiotelephone network for this terminal apparatus such controller also deactivates such a call forwarding if the communication terminal apparatus has been detected as available within the wireless communication device.
Another wireless communication device of the present invention has a controller in order to automatically to activate a call forwarding to the terminal apparatus in the mobile radiotelephone network upon receipt of an item of information concerning the availability of a terminal apparatus via the mobile radiotelephone network for this terminal apparatus such controller also deactivates such a call forwarding if the item of information concerning the availability of the terminal apparatus via the mobile radiotelephone network is revised.
The first-named wireless communication device has the advantage that calls coming in for a terminal apparatus within the wireless communication device [. . . ] can always be received via the mobile radiotelephone network when the terminal apparatus cannot be reached via the wireless communication device but can be reached via the mobile radiotelephone network.
If, given the presence of a message concerning the availability of a terminal apparatus via the mobile radiotelephone network, a call forwarding is activated automatically and, in addition, a call forwarding to an additional wireless communication device is automatically activated, the availability of the terminal apparatus is ensured to a high degree, but the required signaling expense remains very low. Such is ensured within the mobile radiotelephone network, insofar as this additional wireless communication device is in possession of a communication concerning the availability of the terminal apparatus via this wireless communication device.